Display Local Contrast Boosting for SDR Whites Beside HDR Highlights

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Solution Overview

Problem

Electronic devices struggle to maintain the white appearance of standard dynamic range images when displayed alongside high dynamic range images, as the difference in brightness levels can cause white content to appear gray.

Innovation Solution

The solution involves generating a gain map based on high dynamic range image highlights to create regions of locally boosted contrast in standard dynamic range images, adjusting the contrast of standard dynamic range images adjacent to high dynamic range highlights, and applying a temporal filter to smooth transitions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If high dynamic range image content is displayed alongside standard dynamic range image content, then the dynamic range of the display is fully utilized, but the white content in standard dynamic range images appears gray instead of white

Engineering Contradiction:

Improvedynamic range utilizationVSAvoidwhite appearance brightness

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent applies local contrast enhancement by creating a gain map that selectively adjusts luminance values in specific regions adjacent to highlights. This allows different parts of the standard dynamic range image to have different contrast characteristics - regions near highlights receive enhanced contrast while other regions maintain original appearance, thus preserving white content visibility without compromising overall dynamic range utilization

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system performs preliminary processing by extracting highlights from high dynamic range content and generating a gain map before displaying the combined image content. This pre-computed gain map is then applied to the standard dynamic range image to prevent the white appearance issue before it occurs, rather than attempting to fix it after display

Inventive Principle:

Principle #10Preliminary action

2Illumination intensity

If contrast is boosted in regions adjacent to highlights, then white content in standard dynamic range images maintains its appearance, but the complexity of image processing increases

Engineering Contradiction:

Improvewhite content visibilityVSAvoidimage processing complexity

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The patent introduces a gain map as an intermediary element that mediates between the high dynamic range highlights and the standard dynamic range image content. This gain map serves as a preprocessing structure that simplifies the contrast adjustment process by providing pre-computed multiplication factors, reducing the computational complexity of real-time contrast enhancement

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The processing is segmented into distinct steps: highlight extraction from high dynamic range content, gain map generation based on highlight positions and intensities, and selective application to standard dynamic range regions. This segmentation allows each processing stage to be optimized independently and facilitates parallel processing to reduce overall complexity

Inventive Principle:

Principle #1Segmentation

3Speed

If highlights move across the display during playback, then dynamic content is accurately represented, but abrupt contrast adjustments create visual artifacts

Engineering Contradiction:

Improvehighlight movement accuracyVSAvoidvisual smoothness

Core Design Contradiction:

SpeedVSStability of the object's composition

Solution Approach 1:

The patent applies temporal filtering to the gain map at multiple time points during playback, creating a smoothed, time-averaged gain map. This periodic sampling and filtering approach ensures that as highlights move across the display, the contrast adjustments transition smoothly rather than changing abruptly, eliminating visual artifacts while maintaining accurate highlight representation

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The temporal filter acts as a cushioning mechanism that anticipates and prevents abrupt changes in contrast adjustment. By filtering the gain map in advance before application, the system prepares smoothed transition values that prevent sudden visual artifacts when highlights move between frames

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS12567364B1Displays with locally boosted contrast

Publication Date: 2026.03.03 APPLE INC

AI summary

An electronic device may be provided with a display. The display may be configured to display standard dynamic range image content and high dynamic range image content at the same time. The standard dynamic range image content may include one or more regions of locally boosted contrast in regions adjacent to high dynamic range image highlights. This prevents the appearance of grayish whites in standard dynamic range image content while allowing the high dynamic range highlights to take full advantage of the dynamic range of the display. The size and shape of the regions of locally increased contrast may be based on the size and shape of the high dynamic range highlights, the size of the display, the distance between the user and the display, and/or the percentage of the display that is dedicated to high dynamic range image content.